The invention relates to a method for folding a composite profile comprising a hollow body. The hollow body has a closed or virtually closed contour and is made of, in particular, synthetic material, has approximately parallel opposite walls connected by edges, and has a covering sheet fixed against one wall of the body and those regions of the edges close to this wall. The invention also relates to the profiles folded using this parallel covering sheet those regions invention also method.
For a number of applications, and in particular in order to produce bracing frames for the two panes or sheets of glass of double-glazed windows, it is necessary to fold a composite profile comprising a hollow body which has a completely or virtually closed contour and which is made of synthetic material, with one wall covered with a sealing sheet. Thus, a frame of polygonal shape which is generally but not necessarily rectangular is formed.
According to a known method, in each part of the profile in which a fold is to be produced, a transverse notch in one wall of the profile, which notch has a triangular or trapezoidal section so that it possible to produce a fold at the desired angle. For example, at right angles, the notch is located inside the angle, without the material tending to impede folding. With this method, however, the profile has a zone of weakness at the fold.
The object of the invention is to remedy this disadvantage by devising a folding method which is capable of being implemented easily and which allows the production of extremely sturdy folded profiles.
To this end, the invention relates to a method for folding a composite profile comprising a hollow body which has a closed or virtually closed contour and which has approximately parallel opposite walls connected by edges, and a covering sheet fixed against one wall of the body and those regions of the edges close to this wall. A part of the profile in which a fold is to be produced is heated with a temperature gradient extending from the sheet to the wall opposite that to which the sheet is fixed. A hot forming projection or a hot projecting detachable element carried by a tool is in this part pressed against this opposite wall so as locally to bring it closer to or into contact with the wall to which the sheet is fixed and thus to form the region of the future fold. The projection or the tool after having the detachable element disconnected from it is retracted, and, while supporting the edges of the profile so as to avoid them being deformed laterally in relation to the latter, at least one of the parts of the profile which are on both sides of the formed region is pivoted so as to produce in this formed region a fold along a folding line extending transversely to the walls of the body approximately at the level of the limit of the sheet on the edges.
By virtue of the fact that the material is not notched at the fold, no incipient tear is created in the profile.
The method according to the invention can also have one or more of the following characteristics.
In the part of the composite profile in which a fold is to be produced, the body is heated to a temperature at most equal to that at which the material of which it consists becomes soft.
The edges of the profile are supported so as to prevent them from being deformed laterally when the forming projection or the detachable element is pressed against the body.
The support of the edges of the profile so as to avoid their deformation is started after the wall opposite the covering and the wall provided with the covering have been brought closer or into contact.
The folding line is located by aligning a folding articulation axis facing the desired location of this folding line.
The folding line is located approximately at the level of the limit of the sheet on the edges of the body, in a zone covered by the sheet.
The folding line is located approximately at the level of the limit of the sheet on the edges of the body, in a zone which is not covered by the sheet.
After the production of the fold, at least the region of the fold is cooled.
A number of operations are performed simultaneously on one and the same profile. To be more precise, at least one part of the profile is heated while a projection or a detachable element carried by a tool is pressed onto at least one other hot part of the profile, and then a fold is produced in this other part.
The profile is conveyed along and is stopped in successive stations of a folding installation in which stations, respectively, the profile is heated, pressure is applied to one wall of the body and a fold is produced in the profile, and the region of the fold is cooled.
In the same station of the folding installation, a part of the profile is heated. A projection or a detachable element is then pressed onto this part, and a fold is produced in this part in successive operations.
After the stages in which a hot forming projection is pressed against one wall of the profile so as locally to bring it closer to or into contact with the wall to which the sheet is fixed and thus to form the region of the future fold, the projection is retracted. An element forming an insert is accommodated in the region of the future fold, and this is followed by the stage in which, while supporting the edges of the profile, at least one of the parts of the latter which are on both sides of the formed region is pivoted so as to produce the fold.
Prior to the stage during which an element forming an insert is accommodated in the region of the future fold, this element forming an insert is heated in order then to place it while hot in the region of the future fold.
Before the stage in which a hot projecting detachable element carried by a tool is pressed against one wall of the profile, the element is connected to the tool in a detachable manner. At least a part of this detachable element is then heated.
Before the stage in which a hot projecting detachable element carried by a tool is pressed against one wall of the profile, at least a part of this detachable element is heated. The element is then connected to the tool in a detachable manner.
After having disconnected the detachable element and retracted the tool, the detachable element being accommodated in the region of the future fold, and while supporting the edges of the profile so as to prevent them from being deformed, at least one of the parts of the profile which are on both sides of the formed region is pivoted.
The invention, also relates to a profile comprising a hollow body which has a closed or virtually closed contour and which has approximately parallel opposite walls connected by edges, and a covering sheet fixed against one wall of the body and those regions of the edges close to this wall. At least one fold designs an angle, the covering sheet being located outside the angle, and the wall of the body opposite that to which the sheet is fixed has inside the angle a pleat comprising two thicknesses of material welded one against the other or in immediate proximity forming a rigidifying rib extending in the direction of the wall to which the sheet is fixed.
This profile can also have one or more of the following characteristics:
It comprises a folding line extending transversely to the walls of the body approximately at the level of the limit of the sheet on the edges of the body, in a zone covered by the sheet.
It comprises a folding line extending transversely to the walls of the body approximately at the level of the limit of the sheet on the edges of the body, in a zone which is not covered by the sheet.
It comprises at least one fold which defines an angle and in the region of which a reinforcing element is accommodated.
The reinforcing element is embedded in the profile between two thicknesses of material of the profile welded one against the other or in immediate proximity to one another forming a rib opposite the wall to which the sheet is fixed.
The reinforcing element is made of metal.
The reinforcing element is made of a synthetic material.
The reinforcing element is made of poly(styrene/acrylonitrile).
The reinforcing element has an L-shaped cross section.
The reinforcing element has a cross section of general cylindrical shape.
The reinforcing element comprises unevennesses such as grooves or channels.
The reinforcing element has a helical shape.